The starter circuit shown in the figure was found in an old European documentation. The circuit makes use of an SCR which is still common and the diac can be of any type.
This circuit is from a Radio Electronics magazine from December 1958. The indicator instrument is analog...
This configuration was obtained in the SGS manual of linear integrated circuits of 1982. The...
This useful inductance bridge was found in a Radio Electronics from September 1963. The...